Using Hebbian as well as homeostatic models of brain plasticity, the effects of neurofeedback (NFB) are examined from the theoretical perspective of EEG normalization. Within this framework, hyper- and hypo-synchronous oscillations characteristic of abnormal brain dynamics are reversed with NFB training, as seen in several brain disorders including attention-deficit hyperactivity (ADHD) and post-traumatic stress disorder (PTSD). The central thesis put forward is that NFB re-tunes pathological oscillations toward intermediate levels of coupling, which may support self-organized criticality and provide an optimal balance between network flexibility/stability.